Police are investigating the cause of the single-vehicle crash. (Matt Rourke/AP)

An investigation continued Sunday into the cause of a crash on Route 301 in Bowie that killed five children Saturday.

The children — ranging from 5 to 15 years old — were ejected from a 2005 Chrysler Pacifica after it veered off the road and struck several trees, Maryland State Police Capt. Daniel Pickett said at a news conference Saturday. It does not appear that any of the children had their seat belts properly secured, he said.

The children were members of an extended family, he said. Police identified them as London Dixon, 8, and Paris Dixon, 5, who were siblings from Bowie, and Rickelle Ricks, 6; Zion Beard, 14; and Damari Herald, 15, of Washington.

The vehicle’s driver was identified by authorities as Dominique Taylor, 32, who is the mother of London and Paris. Taylor, of Bowie, and Cornell D. Simon of Oxon Hill, Md., who police said was in the passenger seat, were taken to a hospital.

Pickett said Simon, 23, was in critical condition Saturday. He remained at UM Prince George’s Hospital Center on Sunday. Pickett said he did not know the medical condition of Taylor, who was released from the hospital. Police officers have spoken with her, he said.

Taylor’s father, Lee Taylor, said Sunday that it was a difficult time and her family declined further comment.

On social media, another grandparent of some of the children posted Sunday, “My Grandbabies and their cousins were suddenly taken from us in the horrific accident that was on 301 in Bowie yesterday.”

The poster, Sarita Herald, of Oxon Hill, continued, “Our Family is experiencing loss like no other. We need your prayers for comfort peace strength and stability at this time. I’d like to (thank) those who have expressed their condolences and ask that you continue to pray for us . . . My heart is broken.”

Kashmere Cooper, who attended middle and high school with Taylor, said she started crying when she read the news about the crash Saturday.

“I am still heartbroken,” said Cooper, of District Heights. “I know how much she loved her kids. I’ve never lost a child. I can’t even grasp it.”

Cooper said she did not know Paris and London well, but she knew how proud Taylor was of both her daughters, who were students at Northview Elementary School in Bowie. Cooper said Taylor frequently posted about them on social media, where well-wishers shared an outpouring of condolences over the weekend.

Maryland Gov. Larry Hogan (R) tweeted Saturday that he was “deeply saddened by this tragic auto accident in Prince George’s County.”

“Praying for everyone involved, including first responders,” he wrote.

All of the children were ­pronounced dead at the scene.

Police, who received a call about the crash at 5 a.m. Saturday, are investigating the cause and have not ruled out “any possible cause or circumstance,” Pickett said.

He said it appears the group was headed home when the crash occurred between Route 214 and Pointer Ridge Drive. He said he was not sure where they were coming from.

“Every collision we have where we lose life is a tragedy, simple as that,” he said. “When children are involved, it’s more of a tragedy.”

Police said that the northbound lanes of Route 301 were closed for 7½ hours Saturday while they investigated. The speed limit on the stretch of road where the crash took place is 55 mph.

Cars zipped along the wooded stretch Saturday afternoon, many going above the posted speed limit. There was no evidence of the morning’s crash.

Police said the family’s vehicle veered off the left side of the road, where snow covered parts of the ground Saturday afternoon. The area is dotted with trees.

The crash happened not far from Greater Mount Nebo AME Church, among Prince George’s prominent congregations.

Pickett said he was not sure whether ice could have been a factor in the crash.

Prince George’s County Executive Angela D. Alsobrooks (D) said her “heart breaks for the families of these five children whose lives were lost in this tragic accident, as well as the two victims who are being treated for their injuries.”

She said she will offer any resources needed to state police as they conduct their investigation.

County Council Chair Todd M. Turner, who lives with his wife and two children in Bowie, said the crash is among the worst he can recall in the county.

“It’s one of those things that really hits close to home as a parent,” Turner said shortly after driving past the site of the crash.

Last month, a man suspected of driving while intoxicated was charged with vehicular manslaughter following a crash that left three children dead on a different highway in Prince George’s County. That crash prompted lawmakers to announce they would pursue legislation to increase the number of speed cameras along Indian Head Highway.